On May 17, 2006, Chinese patent (patent document number: CN2780937Y) disclosed a blind hinge for furniture door which can realize three-dimensional direction adjustment, comprising a movable base which can be fixed on the door body, an adjustable base which can be fixed on the door frame and a rotary arm connected between the movable base and the adjustable base, wherein the adjustable base comprises a base plate which can be fixed on the door frame, a middle plate which is designed to slide up/down on the base plate and an upper layer adjusting plate which is designed to slide forward/backward on the middle plate, namely the base plate on the door frame is designed as three-layer plate part structure, where the middle plate is formed through alloy casting and is riveted with the lower-layer adjusting plate after re-extrusion. Although the said invention has simple production process, this production process brings some hidden troubles for the quality of hinge. After re-extrusion of alloy casting, changes will take place in the internal structure of the material, such as looser structure and cracking. So, it is difficult for the production process to ensure the reliability of riveting between alloy casting and upper layer regulating plate, leading to unsatisfactory strength of hinge, easy drop of door plate, short service life, complicated structure, many assembly parts as well as high manufacturing and maintenance costs. Therefore, it is necessary to make further improvement.